Improvement in crop productivity, quality and/or resistance to pests, for example, requires the manipulation and expression of both heterologous and endogenous genes in plants and plant tissues. Methods of controlling gene expression include the use of appropriate promoters and other regulators of expression. Through the use of carefully selected promoters, it is possible to control the expression of a particular gene or nucleotide sequence. Promoters can be constitutive (i.e., activated all of the time), developmentally regulated (i.e., activated in response to a particular developmental stage, for example, embryogenesis, senescence, and the like), tissue-specific (i.e., activated only in certain plant tissues, for example, in the root, leaf, seed, and the like), environmentally regulated (for example, activated by temperature and/or light) and/or chemically inducible (i.e., activated by the presence of a particular chemical compound or group of compounds that includes both endogenous and exogenous compounds).
Promoters which are inducible by the external application of a chemical inducer allow control of expression of a nucleotide sequence or gene that is operably associated with the inducible promoter at various stages of plant growth and development as desired. Thus, for example, using a chemically inducible promoter, a plant can be produced that conditionally expresses herbicide or pesticide resistance or that is induced to synchronously produce flowers.
The present invention addresses previous shortcomings in the art by providing compositions and methods for producing promoters that have a pattern of inducibility that is similar to that of the alcohol dehydrogenase (ADH1) system of Aspergillus nidulans using promoters that are not naturally inducible by compounds that induce ADH1 system of A. nidulans. 